﻿/*
* Copyright (c) 2010-2012 Tesla Engine Group
* 
* Permission is hereby granted, free of charge, to any person obtaining a copy
* of this software and associated documentation files (the "Software"), to deal
* in the Software without restriction, including without limitation the rights
* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
* copies of the Software, and to permit persons to whom the Software is
* furnished to do so, subject to the following conditions:
* 
* The above copyright notice and this permission notice shall be included in
* all copies or substantial portions of the Software.
* 
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
* AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
* THE SOFTWARE.
*/


using Tesla.Core;

namespace Tesla.Input {
    /// <summary>
    /// InputCondition contains a condition that must be satisfied by the
    /// input. If a condition is true, then an action can be performed. This
    /// is paired with an InputAction inside an InputTrigger. Conditions
    /// and actions can vary independently of one another, allowing conditions
    /// to be reused.
    /// </summary>
    public class InputCondition {
        /// <summary>
        /// Delegate that contains a condition used by InputCondition.Check(),
        /// in leiu of a subclass.
        /// </summary>
        /// <param name="time">Time elapsed since the last update</param>
        /// <returns>If the condition was satisfied or not</returns>
        public delegate bool DelegateInputCondition(GameTime time);

        private DelegateInputCondition _condition = null;

        /// <summary>
        /// Creates a new instance of <see cref="InputCondition"/>.
        /// </summary>
        protected InputCondition() {}

        /// <summary>
        /// Create a new InputCondition with the specified delegate function.
        /// </summary>
        /// <param name="condition">DelegateInputCondition</param>
        public InputCondition(DelegateInputCondition condition) {
            _condition = condition;
        }

        /// <summary>
        /// Check if the condition has been satisfied or not.
        /// </summary>
        /// <param name="time">Time elapsed since the last updatet</param>
        /// <returns></returns>
        public virtual bool Check(GameTime time) {
            if(_condition != null) {
                return _condition(time);
            } else {
                return false;
            }
        }
    }
}
